Headphone



FIG. 1 is a perspective view of a headphone showing the design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof; and,

FIG. 6 is a right side view thereof.

The broken lines depict environment that forms no part of the claimed design. 

CLAIM I claim the ornamental design for a headphone, as shown and described. 